Torpedo exploder mechanism



1930 J. M. KENDALL ETAL 2,951,951

TORPEDO EXPLODER MECHANISM 5 Sheets-Sheet 1 .F'iled May 26, 1947 Nov. 29, 1960 J. M. KENDALL ETAL 2,961,961

TORPEDO EXPLODER MECHANISM Filed May 26, 1947 5 Sheets-Sheet 2 94 usuz 97|o| as 99 121 133 12a 93 awe/rm JMKendaZl Lil 71570111112192 Nov. 29, 1960 Filed May 26, 1947 J. M. KENDALL ET AL TURPEDO EXPLODER MECHANISM i ll Sheets-Sheet 3 1960 J. M. KENDALL ET AL 2,961,961

TORPEDO EXPLODER MECHANISM Filed May 26, 1947 5 Sheets-Sheet 4 A -'r ml 1 1960 J. M. KENDALL ETAL 2,961,951

TORPEDO EXPLODER MECHANISM Filed May 26. 1947 t 5 Sheets-Sheet 5 I9l L; 38 I: 327 316 362 34 328 r I 1 Ws 332 370 349 329 I92 y A f {45 villa/211111111 United States Patent TORPEDO EXPLODER MEGHANISM' James M. Kendall, Coral Hills, Md, and Charles F. Holdrege, Omaha, Nebr.

Filed May 26, 1947, Ser. No. 750,615

16 Claims. 01. 102-17 (Granted under Title as, US. Code 1952 sec. 266) This invention relates generally to exploder mechanisms for torpedoes and includes means for preventing the premature firing of a torpedo during a broach thereof, a broach being herein defined as any phase of the travel of the torpedo during its run in which the warhead or any part thereof moves out of the water. The present invention is particularly adapted for, but not exclusively limited to, use with a homing torpedo. A homing torpedo is known in the art of marine warfare as one which is provided with a pickup deviceresponsive to some characteristic of the target vessel, such as a microphone responsive to the noise of vibration of the propeller mechanism, and which employs means controlled by the signal of the pickup device to steer the torpedo to the target vessel. If the torpedo misses the target vessel on the first pass, it then makes successive passes until either it strikes the target vessel or its engines run down.

Torpedoes are usually equipped with-any one of several types of exploder mechanisms for causing the firing of the main charge when the torpedo strikes its target. Many of the exploder mechanisms include an inertia actuated switch which closes the firing circuit of the exploder mechanism in response to the sudden impact of the torpedo with its target. However, torpedoes are known to broach during their runs. This is particularly the case with a homing torpedo when fired from an underwaterposition and adapted to make an upsweep approach to the target vessel so as to strike the bottom of the vessel, preferably the keel. In such case, if the torpedo should miss the target vessel, it may leap out of the water and,

when it re-enters same, the inertia switch will be actuated due to the impact, the firing circuit closed and the torpedo exploded. Thiswill not only apprise the target vessel that it is under attack but the explosion destroys the torpedo itself, rendering it impotentfor making a return run and a second strike atthe target vessel. Another and infrequent case of surface broaching, but one which nevertheless occurs, is in the case of a surface running torpedo which passes from the crest of one large wave, through the trough, and into the crest of'the next wave. As before, the resultant-impact may actuate the inertia switch, close the firing circuit and explode the tr-" pedo.

g The object of this invention is to provide a firing circuit for a torpedo exploder including means for rendering the exploder ineffective during a broach of the torpedo andfor a short intervalthereafter suflicient to allow the motion of the torpedo to become stable.

Another object of the present invention is to provide a firing circuit for a torpedo exploder including a differential fluid pressure actuated switch for rendering theexploder ineffective during a broach of the torpedo and for a short interval after it re-enters and becomes submerged in the water.

lQQ

A further object of the present invention is to provide a firing circuit for a torpedo exploder including a differ the water following a broach, which switch is adapted to be operated by the differential in fluid pressure existing between the nose and the side wall of the torpedo.

An additional object of the present invention is to provide an electric firing circuit for a torpedo including R- C components having a charging time constant of several seconds and a discharging time constant of approximately one second, or less, whereby the firing circuit is rendered ineffective for an interval exceeding each broach time of the torpedo and is rendered effective within a relatively short time interval after each broach.

Still other objects, advantages, and improvements will be apparent from the following description, taken in connection with the accompanying drawings, in which:

Fig. 1 is an internal view of the warhead of a homing" torpedo, the parts comprising the exploder mechanismof the present invention being shown schematically;

Fig. 2 is a view similar to Fig. 1 but showing the Fig. 3A is a view, partly in elevation and partly in sec tion, showing the upper portion of the exploder mechanism including the arming switch;

Fig. 4 is a view taken substantially on the section line 4-4 of Fig. 3A and showing the arming switchin detail;

Fig. 5 is an elevational view of the upper portion of the exploder mechanism housing as viewed from the right in Fig. 3A and showing locks the rotor of the arming switch in the armedposition;

Fig. 6 is a sectional detail view the section line 66 of Fig. 5; v

Fig. 7 is a sectional view of the differential fluidpressure actuated switch;

of thedetent, taken on Fig; 8 is a graph showing the variation of the' fluid such as an electric motor or a steam or compressed air" turbine and the operating medium for the motive means, such as batteries, steam generating apparatus; or compressed air storage tanks, and the automatic steering apparatus. A rear handhole is comprisedby an inturned cylindrical section 16 of the torpedo'casin'g 10, this cylindrical section having a bottom flange 18. A handhole cover 21 is secured to the bottom flange 18 by stud bolts 22, a gasket 23 of neoprene rubber, or other suitable material, being positioned intermediate the handhole cover and the bottom flange of the casing. Thisrear handhole provides access to the motive means and the storage of generating apparatus for the automatic steering apparatus.

Patented Nov. 29, 1960 the position of the detent which operating medium and the 1 Similarly, a front hand- 3 hole is provided in the forward compartment, this handhole being likewise formed by an inturned cylindrical section 17 of the torpedo casing 10, and having a bottom flange 19. This forward handhole provides for the insertion of the exploder mechanism 80, to be later de scribed.

The removable bulkhead 12 is secured in place by an annular brace 13, which is mounted on the interior wall of the torpedo casing as by brazing, soldering, welding, or the like, and in turn mounts a shouldered ring 14 which receives the bulkhead.

The forward compartment is subdivided by a fixed bulkhead 24 which is secured at its periphery to the interior wall of the torpedo casing 10, again as by soldering, welding, brazing, or the like. The space between the removable bulkhead 12 and the fixed bulkhead 24 is filled with the main explosive charge 15 and the space between the fixed bulkhead 24 and the nose of the torpedo is provided for the sound pickup 36-36 and the exploder mechanism 80, which latter contains the principal components of the present invention. Referring to Fig. 2, it will be seen that the fixed bulkhead 24 has a hole therethrough over which a cylindrical casing 28 is fitted, this casing forming an extension of the space for the main explosive charge 15. The cylindrical casing 28 has a bottom flange 27 through which rivets 26 pass to secure the casing to the bulkhead and a top rim flange 29 to which a cover 32 is secured by bolts 31. The cover 32 has a *circular hole therein into which a casing 33 having a rim flange 34 is fitted, this casing containing the booster charge 35. The booster charge 35 in the casing 33 is thus surrounded by the main explosive charge 15 in the cylindrical extension 28 on the bulkhead 24.

Mounted in the forward section of the torpedo casing 10 is the aforesaid pickup comprising a plurality of microphones 36-36, preferably four (4) spaced equally around a circle adjacent the nose, but only two (2) being shown. Each microphone 36 is enclosed by metal casing 38 which prevents the microphone from being affected by air pressure. The microphone casings 38 are secured to the inner wall of the torpedo casing 10 by stud bolts 40, spacer nuts 39 being mounted under the casings. Each microphone casing is enclosed by a box 42. The boxes 42 are preferably made of pure gum rubber, at least two (2) ply with metallic reinforcement between the plies, or some similar material which is non-conducting to sound vibrations. The boxes 42 are each provided with valves 43 in their tops through which the air may be withdrawn, leaving a vacuum within the boxes and surrounding the microphone casings 38-38. Yoke straps 45 and stud bolts 44 are provided for securing the boxes 4242 to the inner wall of the torpedo casing 10, the stud bolts 44 being screwed at their inner ends into suitable holes in the torpedo casing 10 and at their outer end passing through suitable holes in the yoke straps 45 and having suitable nuts 46 abutting the latter. A suitable conduit 50 passes through the top of each box 42, and these conduits are joined in a Y fitting 54 to a main conduit 55 which extends to the rear section of the torpedo casing 10. Suitable conductors 48 pass through the branch conduits 50--50 and the main conduit 55 to the rear section of the torpedo casing 10 and to the automatic steering apparatus therein. The automatic steering apparatus may be of any suitable type employed in homing torpedoes, such, for instance, as the automatic steering apparatus described and illustrated in U.S. Patent No. 1,121,563 to Karl 0. Leon.

The dynamic pressure intake and low pressure transmission system of the present invention is generally similar to that illustrated and described in the co-pending application of Ernest R. Haberland, Serial No. 573,623, for Torpedo Arming Device, filed January 19, 1945. A pressure intake element 63 is secured to the inner wall of the torpedo casing 10 and over a hole 60 in the nose end thereof, as by brazing, soldering, welding, or the each hole.

like. A screen element 62 is positioned over the mouth of the intake element 63 and prevents the entry of foreign matter into the conduit 65. The screen element 62 is secured in place by a screw threaded insert 61 fitted in the hole 60 in the nose wall of the torpedo casing 10. A pressure intake 65 enters the intake element 63 through a packing gland 64. The conduit 65 has elbows 66-66 therein and extends to the inturned cylindrical section 17 of the torpedo casing 10 which forms the forward handhole, entering this section through a packing gland 69.

A low pressure transmission conduit 75 extends from a hole 70 in the side wall of the torpedo casing 10, has elbows 76-76--76 therein, and also terminates in the inturned cylindrical section 17 of the torpedo casing 10, entering this section through a packing gland 79. The low pressure transmission conduit 75 is passed through the fixed bulkhead 24 by a bushing 77, locknuts 78--78 being mounted on the bushing on either face of the bulkhead. As before, an intake element 73 is secured to the inner wall of the torpedo casing 10 over the hole 70 therein, as by brazing, soldering, welding, or the like. The conduit 75 enters the intake element 73 through a packing gland 74. A screen element 72 is also secured over the mouth of the intake element 73 and prevents the entry of foreign matter into the low pressure transmission conduit 75. The screen element 72 is secured in place by a screw threaded insert 71 which is fitted in the hole 70 in the wall of the torpedo casing 10.

The water pressure at the pressure intake hole 60 in the nose wall of the torpedo casing 10 corresponds to the ordinate of maximum positive pressure and the water pressure at the hole 70 in the side wall of the torpedo casing 10 corresponds to the ordinate of maximum negative pressure, as shown in the graph on Fig. 8 which illustrates the variation in dynamic pressure between the nose and side wall of the torpedo. Zero pressure on the graph, of course, is not actually zero pressure but the pressure of the surrounding water at the depth of submergence of the torpedo, this pressure being taken as a reference from which to measure the variations in dy namic pressure represented by the quantity /2 v where p is the density of the water and v is the velocity of the torpedo in knots.

The exploder mechanism 80 is shown in detail in Figs. 3 and 3A. This mechanism is mounted on a generally cylindrical base 81, Fig. 2, which has a circumferential boss 83 and an eccentric boss 84 on its top, a circumferential shoulder 82 adjacent its top, a circumferential bottom flange 86, and an enlarged central bore 87, formed with a counterbore 88, for receiving the impeller wheel 135, to be later described. The circumferential bottom flange 86 is provided with a first series of arcuately spaced holes 92, counterbores 93 extending from the bottom flange in concentric relationship with Stud bolts 94, with washers 96 under their heads, extend through the holes 92 and into the bottom flange 19 on the inturned cylindrical section 17 of the torpedo casing 10 to secure the exploder mechanism 80 in place in the forward handhole. A second series of arcuately spaced holes 97 is also formed in the circumferential bottom flange 86, these also being provided with concentric counterbores 98 extending from the top of the flange. A guard plate 99 is secured over the bottom of the cylindrical base 81, stove bolts 101 extending through suitable holes in the guard plate and the holes 97 in the circumferential bottom flange 86, these latter having nuts 102 and locknuts 103 on their ends positioned Within the counterbores 98 in the bottom flange 86.

The side wall of the circumferential bottom flange 81 has five (5) annular grooves 104, 107, 108, 111, and 112, therein. O-ringgaskets 106, 109, and 113 are positioned in the top groove 104, middle groove 108, and the bottom groove 112, respectively. The annular groove 107, intermediate the packing ring grooves 104 and 108, registers with the packing gland 69, Fig. 2, at the endof the pressure intake conduit 65, the latter extending through the inturned cylindrical section 17 of the torpedo casing similarly, the groove 111, intermediate the packing ring grooves 108 and 112, registers with the packing ring gland 79 at the end of the vacuum transmission conduit 76, the latter also extending through the inturned cylindrical section 17 of the torpedo casing 10, when the exploder mechanism 80 is in place. A bore 114 extends transversely through the base 81 from the annular groove 111 and is closed at its inner end by a screw plug 116 extending outwardly from the counterbore 88 in the base; similarly, a bore 117 extends transversely of the base 81 from the annular groove 107 and is closed at its inner end by a screw plug 118 extending outwardly from the bore 87 in the base 81. A bore 119 extends longitudinally through the base 81 and the circumferential boss 83 on the top thereof, this bore intersecting the transverse bore 114 and being closed at its outer end by a screw plug 121 extending upwardly from the bottom flange 86 of the base; similarly, a bore 122 extends longitudinally through the base 81 and the circumferential boss 83 on the top thereof, this bore intersecting the transverse bore 117 and likewise being closed by a screw plug 123 extending upwardly from the bottom flange 86 of the base.

The impeller mechanism for operating the arming switch SW-1 is mounted in the enlarged cylindrical bore 87 in the base 81. The housing for this mechanism is comprised by a circumferential mounting flange 124, an integral bottom plate 126, and a generally cylindrical housing section 127, the latter conforming to the shape of the impeller wheel 135 throughout most of its periphery but having a trailing section 128 at its rear. An integral guide plate 129 is spaced below the bottom plate 126 and underlies the cylindrical housing section 127, this plate forming with the bottom plate 126 a substantially Venturi shaped nozzle 131 and at its rear forming with the trailing section 128 of the housing an exit aperture 132. The circumferential mounting flange 124 is received within the counterbore 88 of the enlarged cylindrical bore 87 in the base 81, and machine screws 133 extend through suitable holes in the mounting flange 124 and are received in suitable threaded holes in the bottom of the counterbore to secure the housing in place. The position of the forward handhole 17 in the torpedo casing 10 is such that the housing 127 disposed therein is within the streamlines of the torpedo casing 10 and thus does not cause undue drag but nevertheless permits ready ingress of the water through which the torpedo passes into the Venturi nozzle 131,

The impeller wheel 135 has blades 136 thereon, and this wheel is mounted within the substantially cylindrical section 127 of the impeller housing on a shaft 137. This shaft extends freely through the side walls 140-140 of the cylindrical housing section 127 and is journalled in the arms 139-139 of a bifurcated bracket 138. The bracket 138 is secured on the bottom of the enlarged cylindrical bore 87 in the base 81 by machine screws 141. A worm 142 is mounted on the impeller shaft 137, being secured thereon by a locknut 143. An integral cylindrical boss 89 having a bore 91 therethrough extends from the bottom of the enlarged cylindrical'bore 87 in the base 81 and longitudinally of the latter, this bore continuing upwardly through the eccentric boss 84 on the top of the base 81. A countershaft 144 is journalled in the bore 91 through the cylindrical boss 89 by a bushing 146 and three (3) integral packing ring flanges 147, 151, and 153, formed on the countershaft, the uppermost flange 153 being flush with the top of the eccentric boss 84 on the base 81. A compound packing gland is comprised by an O-ring gasket 152 fitted between the uppermost flange 153 and the intermediate flange 151, and a:

stuffiing box 149 and a second O-ring gasket 148 positioned between the intermediate flange 151 and the bottom flange 147.

A worm gear 157 is mounted on the lower end of the countershaft 144, this gear meshing with the worm 142 on the impeller shaft 137. The worm gear 157 has an integral hub 156, a washer 154 being positioned intermediate the upper end of the hub 156 and the bushing 146 mounted in the bore 91 through the cylindrical boss 89, and a washer 158 being likewise positioned adjacent the lower face of the hub 156, the latter being held securely in place by a castle nut 159 mounted on the lower end of the countershaft 144. A cotter key 161 extends through one pair of diametrically aligned slots in the castle nut 159 and through a suitable hole in the countershaft 144 to secure the castle nut and the worm gear 157 to the countershaft.

A spur pinion 162 is secured to the top of the counter'- elongated shaft 165, this latter being the driving shaft' for the arming switch SW-l, as will be later described. The shaft 165 is journalled at its bottom in a thrust hearing 168 mounted in a suitable hole in the eccentric boss 84 on the top of the cylindrical base 81, a washer 167 being interposed between the spur gear 164 and the thrust bearings 168.

The firing components of the exploder mechanism 80, with the exception of the arming switch SW-l, are enclosed by an intermediate structure mounted on the cylindrical base 81 and having a cylindrical top plate 169. Stay bolts 177 are screw threaded at their upper and lower ends and mounted at their lower ends in suitably threaded holes 176 in the circumferential boss 83 on the top of the cylindrical base 81 and at their upper ends pass freely through holes 171 in the cylindrical top plate 169. The cylindrical top plate 169 is formed with suit able recesses 172 in its upper face to receive nuts 178 fitted on the stay bolts 177 adjacent the upper ends of the latter. prised by a plurality of plates, is provided transversely of the intermediate structure. The partition member 184 is secured intermediate pairs of sleeves 183186, preferably hexagonal in shape, encompassing each stay bolt, sleeves 183 being positioned intermediate the circumferential boss 83 on the cylindrical base 81 and the partition member 184, and the other sleeves 186 being positioned intermediate the partition member and the cylindrical top plate 169. The elongated driving shaft 165 for the arming switch SW-l passes freely through a hole 188 in the transverse partition member 184. A-

cylindrical sleeve 174 encloses the intermediate structure, this sleeve encompassing the cylindrical top plate 169 and resting on the shoulder '82 on the cylindrical base 81.

The fluid pressure actuated differential switch SW-2, which discharges the firing capacitor for the electroresponsive squib 268 when the torpedo is on a broach, as will be later described, is mounted on the transverse partition member 184 by angle brackets 191, bolts 189 extending through one leg of each angle bracket and the partition member 184, and bolts 192 extending through the other leg of each angle bracket and the end plates 326-327 of the switch. A conduit 196 extends from the switch to the longitudinal bore 119 in the base 81. Similarly, a conduit 261 extends from the switch to the longitudinal bore 122 in the cylindrical base 81.

A battery BA is secured to the top of the cylindrical base 81 by angle brackets 297, a screw 206 extending through one leg of each angle bracket and into the battery casing, and a machine screw 20-8 extending through the other leg of each' angle bracket and into the top of the base 81. i

The inertia switch SW3, which fires the eleetroresponsive squib 268 when the torpedo strikes its target, as will be later described, is also secured to the transverse par tition member 184 by an angle bracket 211, a bolt 209 tition member and one leg of the angle bracket and a bolt A partition member 184, preferably com- 212 extending through the other leg of the angle bracket and the bottom disc 386 of the switch.

A capacitor C is mounted in a can 216 having a base flange 214 and terminals 217 and 218 extending through the top of the can. Bolts 213 extend through suitable holes in the base flange 214 and the transverse partition member 184 to secure the capacitor in place.

Conductors from the battery BA, differential fluid pressure actuated switch SW-Z, and the inertia switch SW-3 extend through a suitable grommet 187 in the transverse partition member 184 to the capacitor C, the arming switch SW-1, and the electroresponsive squib 260.

The arming switch SW-l is mounted in a superstructure comprised by a main body 225 and a cover plate 226. The main body 225 has a vertically extending reinforcing web 223 thereon and a toe flange 221 at its base, through which flange some of the stay bolts 177 extend, the latter having additional nuts 182 at their tops and both washers 181 and lock washers 179 under the nuts. At its top the main body 225 is formed as a cylindrical section 227, this section having a cylindrical bore 231, Fig. 4, therein for the reception of the rotary member 270 of the arming switch SW-1, as will be later described. Likewise, the cover plate 226 has a vertically extending reinforcing web 224 thereon and a toe flange 222 at its base, through which others of the stay bolts 177 extend, the latter also having additional nuts 182 at their tops and both washers 181 and lockwashers 179 disposed under the nuts. At its top the cover plate 226 is formed as a disc section 228, Fig. 5, which registers with the cylindrical section 227 on the main body 225. The cylindrical section 227 of the main body is formed with an integral upwardly extending car 229 and the disc section 228 of the cover plate 226 is formed with a registering upwardly extending car 230, and the two parts are held together by screws 232 which extend freely through the ear 230 and are received in suitable threaded holes in the car 229. The vertically extending reinforcing web 224 on the cover plate 226 terminates in a cylindrical boss 234 eccentrically disposed on the disc section 228. A pair of horizontally disposed reinforcing ribs 236238 is integrally formed on the cover plate 226 and extend radially from the cylindrical boss 234 on either side of the latter. A second eccentrically positioned integral boss 240 is formed at the juncture of the horizontal reinforcing rib 236 and the vertical reinforcing web 224, for a purpose to be later stated. Disposed below the horizontal reinforcing ribs 236238 and in parallelism with the latter there is a second pair of horizontal reinforcing ribs 242-244, these extending transversely from the vertical reinforcing web 224 and being disposed on either side of the latter.

The main body is faced off at 233, as best shown in Fig. 4, to form a recess for the operating parts of the arming switch SW-1, this faced olf section merging with the cylindrical bore 231 in the cylindrical section 227. The cylindrical section 227 of the main body 235 is formed at one side with a tangential enlargement 237 which provides a tangential recess 239, wherein there is mounted the bearing bushing 245 for the upper end of the driving shaft 165 of the arming switch and a slip clutch 166296, to be later described. The top of this tangential enlargement forms with the cylindrical top 227 of the main body and the car 229 thereon a shoulder 241. The tangential recess 239 in the enlarged section 237 of the main body merges with the recess 233 in the face of the main body along a shoulder 235 formed in the wall of the main body, this shoulder being also positioned at the juncture of the bore 231 in the cylindrical section 227 and the recess 233 in the face of the main body.

A longitudinal bore 246 extends through the reinforcing web 224 on the cover plate 226 and terminates in an L-shaped cavity 250 in the cylindrical boss 234 on the cover plate. In the assembled relationship of the explorer mechanism, this longitudinal bore through the reinforcing web 224 registers with a hole 173 in the top plate 169 of the intermediate structure, the bore 246 and the hole 173 forming a passageway for conductors 415 and 416 to the arming switch SW-l and conductors 418 and 419 to the electroresponsive squib 260. A hole 248 extends from the inner face of the cover plate 226 and communicates with the longitudinal bore 246 through the web 224, this hole providing for passage of the conductors 415 and 416 to the arming switch SW-l mounted in the recess 233 in the main body 225. The L shaped cavity 250 in the cylindrical boss 234 on the cover plate 226 is covered by an inspection plate 252 which is fitted in a shouldered recess in the cylindrical boss. A transverse bore 256 extends from the inner face of the cover plate 226, approximately half way through the cylindrical bossto the leg of the L shaped cavity 250, the bore 256 forming a chamber for the electroresponsive squib 266 and the bore 258 forming a continuation passageway for the.

conductors 418 and 419 to the electroresponsive squib.

A bore 251 is formed from the back face of the main body 225 and extends into the cylindrical section 227 in communication with the bore 231 extending from the front face of the cylindrical section, the bore 251 receiving a cup 253. The cup 253 has a radially extending flange 243 at approximately its mid-section through which suitable machine screws 261 pass to secure the cup to the cylindrical section 227 of the main body. The cup 253 is screw threaded on its periphery adjacent the top for receiving a cover 259 having a thin top and a screw threaded skirt. A sub-booster charge 255 is placed within the cup 253. Formed in the bottom of the cup 253 there is a hole 263, this hole communicating with the cylindricalbore 231 in the cylindrical section 227 of the main body and being aligned with the concentric bores 256-258 in the disc section 228 of the cover plate 226 in the assembled relationship. The hole 263 in the bottom of the cup 253 forms a chamber for a tetryl lead 265. When the explorer mechanism is in place in the forward handhole 17, the cup 253 is aligned with and closely adjacent to the casing 33 carried by the cover 32, which casing, as previously stated, contains the main booster charge 35.

The rotor of the arming switch SW-1, Figs. 3A and 4, is comprised by a disc 270 having a worm gear 266 on its periphery. The disc 270 is mounted in the cylindrical bore 231 in the cylindrical section 227 of the main body, being secured to a shaft 269 for rotation therewith. This shaft is journalled in aligned bearing holes 267 and 268 in the faces of the main body 225 and the cover plate 226, respectively. On either side of one diameter of the rotary disc 270 and adjacent the periphery of the latter, there are formed holes 271 and 273, these holes being adapted to receive detonators 275275. Two (2) holes are shown since, for certainty of firing, it may be desirable to duplicate the first three (3) components of the detonator train, that is the electroresponsive squib 260, detonator 275, and the tetryl lead 265; if, however, it should be desired to use only one (1) detonator 275, then of course only a single hole, 271 or 273, in the rotary disc 270 and positioned on the referenced diameter would be provided.

On the inner face of the rotary disc 278 there is formed an arcuate recess 281 of approximately half the thickness of the disc, this recess being disposed diametrically opposite the holes 271 and 273, and being symmetrically disposed with respect to the aforesaid diameter inter mediate these holes. An arcnately shaped insulating block 282, preferably of some phenolic condensation product such as Bakelite, is positioned in the arcuate recess 281 in the rotary disc 270 and secured to the latter by a machine screw 283. The insulating block 282 has a radially extending wiping blade 285 embedded therein.

Mounted below the rotary disc 270 there are two (2) L-shaped insulating blocks 286 and 290, also preferably of some phenolic condensation product such as Bakelite,

thesebeing positioned in foot-to-foot relationship so, as to form a channel between the legs of same, and the blocks being secured to the inner face of the cover plate 226 by machine screws 288 extending freely through the blocks and received in suitable threaded holes in the inner face ofthe cover plate. Two (2) aligned contact blade members 287 and 289 are mounted between the feet of the insulating blocks 286 and 290 and extend into the channel intermediate the legs of the latter, these being positioned in close juxtaposition to the circle of sweep of the wiping contact blade 285 carried by the rotary disc 270. Conductors 415 and 416 are connected to the contact blade members 287 and 289, respectively.

As best shown in Fig. 4, a bore 247 extends from the aforesaid shoulder 241tangentially of the cylindrical bore .231 in the main body, and the aforesaid bearing bushing 245 is mounted inthis bore. The bearing bushing 245 ,is provided with an axial bore 249 in its inner face in which the upper end of the driving shaft 165 for the rotary disc 270 is received. The driving shaft 165 is formed with asquare section 166, comprising the aforementioned clutch-adjacent its upper end and the face of the bushing 245. A clutch sleeve 293 has a bore 294 therethrough, this bore being formed as a square section 296 adjacent the upper end. The clutch sleeve 293 is'fitted over the driving shaft 165 with the square section 296 of the bore .mat-ing-withthe square section, 166 of the driving shaft, and is normally held in such engaged position by a compression spring 299 which surrounds the driving shaft 165. A washer 298 is positioned intermediate the upper end of the compression spring 299 and the lower end of the clutch sleeve 293, and the compression spring at its bottom abuts the shoulder 235 intermediate the recess 233 in the main body 225 and the tangentialenlargement 237 of the cylindrical section 227. At its mid-section the clutch sleeve 293 is formed with an integral worm 295 which meshes with the Worm gear on the rotary disc 270.

In order to stop the rotary disc 270 with the detonators 275-275 carried thereby in alignment with the electroresponsive squib 268 and the tetryl lead 265, and with the wiping blade 285 in engagement with the contact blades 287 and 289, a detent mechanism is provided. As previously stated, and as shown in Fig. 5, the auxiliary boss 240 is formed on the cover plate 226, this boss being contiguous to the cylindrical boss 234 mounting the inspection plate 252. A bore 276 is formed through the auxiliary boss 240, Fig. 6, and a concentric bore 278 of lesser diameter continues through the cover plate 226. A bore 304, in alignment with bore 278, is formed in disc 270. This bore is enlarged at 300 and terminates in a counterbore 30 2 in the opposite face of the disc. A detent 306 is mounted in bore 300, this detent having a cylindrical body, an axial bore 308 therein, and a rounded nose 310. The counterbore 302 is closed by a spring plate 312 force fitted therein, and a compression spring 314 is interposed between the spring plate 312 and the bottom of the axial bore 308. The detent normally has its rounded nose 3'10 projecting through bore 304 and slightly beyond the inner face of the cover plate 226 into bore 278. The bore 276 is closed by a screw plug 280. The boss 240 is angularly displaced from the aforesaid diameter intermediate the holes 271-473 in the rotary disc so that the rounded nose 310 of the detent 306 will enter the hole 278 and lock disc 2'70 in a position to complete the detonator train and bring the wiping contact blade 285 into engage ment with the fixed contact blades 287 and 289, thereby also completing the arming circuit for the exploder, as will be later described.

Referring now to Fig. 7, there is here shown in detail the fluid pressure actuated diflerential switch SW-2 which discharges the capacitor C by completing a discharge path thereto when the torpedo is on a broach. This switch is disclosed and claimed in the copending. application of James M. Kendall for Fluid Pressure Differen- 10 .tial Switch, Serial No. 758,969, filed July 3, 1947. [The switch is contained principally in a cylindrical body 320 having a reduced end portion 321, a rectangular groove 323 being formed around this portion of the body adjacent its end, and an opposite end portion 332 which terminates in a rectangular groove 324. The cylindrical body 3 28 is supported by two (2) end plates 326 and 327, having inwardly extending hubs 328 and 329, respective ly. The end plate 326 has a bore 332 extending through its hub 328 and approximately to the inner face plane of the end plate, and the end plate itself has a central hole 334 for receiving the conduit 261. The conduit .261 is secured in the central hole 334 by a fillet 336 of silver solder. Similarly, the end plate 327 has a bore 333 extending through its hub329 and approximately to the inner face plane of the end plate and a counterbore 325 in the inner face .plane of the end plate, which counterbore forms a clearance for the flexure of a diaphragm 343, as. will be later described. The end plate itself has a central hole 337 through which the conduit 196 extends. As before, the conduit 196 is secured in the hole 337 by a fillet 339 of silver solder. The end plates 326 and 327 are provided with aligned holes 340 and 341, respectively, for the reception of the screws or bolts 192.

Diaphragms 322 and 343, of synthetic rubber, or other suitable material, are secured over the end portions 322 and 321, respectively, of the cylindrical body 329 of the switch. Each of the diaphragrns 342 and 343 consists of an end disc with an annular projection 344 therein for increasing flexibility of the disc, and a cylindrical skirt 345, a rectangular bead 346 being formed at the bottom of the skirt on its inner periphery. The face of the end portion 322 is formed with an arcuate recess 348 for receiving the annular projection 344 in the diaphragm 342. The head 346 of the diaphragm 342 fits behind the rectangular rim 325 on the end portion 322, and the bead 346 of the diaphragm 343 seats in the rectangular groove 323 in the end portion 321 of the cylindrical body. Annular gaskets 347-347, of cork-neoprene or other suitable gasket material, are positioned between the diaphragm 342 and the bottom of the bore 332 in the cylindrical hub 328 on the end plate 326 and between the diaphragm 343 and the bottom of the bore 333 in the cylindrical hub 329 on the end plate 327. The end plates 326 and 327 and the cylindrical main body 326 are held together by long filister head screws 357 which extend freely through suitable holes in the endplate 3 27 and are received in suitable threaded holes in the end plate 326. The end portion 322 is provided with an axial bore 350 concentrically positioned with respect to the arcuate recess 348 in the face of the end portion, this bore forming a piston chamber, as will be later described. An axial bore 349 extends through the opposite end portion 321 and partially through the main body 320, the bottoms of the bores 349 and 350 being separated by an integral wall or partition member 352 through which, however, an axial bore 354 extends. A counterbore, concentrically positioned with respect to the axial bore 349, extends from the face of the end portion 321, this counterbore being formed in three (3) sections, a first section 351 forming a chamber for the inward flexure of the diaphragm 343, a threaded section 353, and a rectangular groove 355 at the bottom of the threaded section 353 and of slightly larger diameter than this section. A radial hole, closed by a screw plug 371, is formed through the main body 320 and communicates with the axial bore 349 therein, this hole be ing an oil filling opening.

A piston 356 has a head which is adapted for limited reciprocation in the axial bore 350 and abuts the diaphragm 342. The piston also has a stem 358, which passes through the central bore 354, and an elongated extension 362, the juncture of the stem 358 and the elonmounted on the elongated extension 362 of the piston sparse;

11 Fstem 358 there is a contact disc 366 which has a central hole 368 and a peripheral rim 370, this disc preferably being of brass and silver plated. The hole 368 in the contact disc 366 receives the elongated extension 362 on the piston 356, and the disc abuts the shoulder 360.

A spring retainer 361 is formed as a cylindrical threaded member with an integral elongated hub 365, a groove 363 being provided on the inner face thereof intermediate the cylindrical threaded member 361 and the integral elongated hub 365. An axial bore 367 is formed through the elongated hub 365, and a diametral slot 359, adapted to receive a screw driver, is formed in the outer face of the cylindrical threaded member. This threaded cylindrical member is received within the threaded section 353 of the counterbore through the end portion 321 and, by reason of the enlarged diameter of the rectangular groove 355 around the counterbore, this member can be screwed all of the way down to the bottom of the counterbore. The axial bore 367 through the elongated hub 365 of the spring retainer receives the cylindrical extension 362 on the stem 358 of the piston 356 and forms a guide therefor. A coiled compression spring 369 is interposed between the contact disc 366, and inside the peripheral rim 370 thereof, and the spring retainer 361, the outer end of this spring being received in the annular groove 363.

Approximately midway of the cylindrical body 320 and spaced inwardly from the integral partition 352, there is provided a pair of diametrically opposed holes 372372. Flanged bushings 374374 are fitted in these holes, respectively, and a contact rod 378 extends through one bushing 374 and a contact rod 380 extends through the other bushing 374. The space between each of contact rods 378 and 380 and the flanged bushing 374 individual thereto, and for some distance along each contact rod from either end of the bushings, are filled with glass 'as at 376, the glass preferably being first melted and then poured into place. Preferably, both the bushings 374- 374 and the contact rods 378 and 380 are made of Kovar, an alloy that has approximately the same coefficient of expansion as glass. On the inner ends of the contact rods 378 and 380 there are force fitted contact rings 382 and 384, respectively these preferably being made of silver.

The relative proportions of the respective parts of the fluid pressure actuated differential switch SW-2 are so selected that, with the piston 356 in its outermost position and the diaphragm 342 in its approximately plane position, the contact disc 366 will be held by the coiled compression spring 369 against the shoulder 360, and likewise against the contact rings 382 and 384 carried by the contact rods 378 and 380, respectively. This is the position of the parts when the fluid pressures in conduits 196 and 201 are equal.

The interior of the fluid pressure actuated differential switch SW-Z, comprised by the main bore 349 and the axial bore 350, is completely filled with a suitable fluid such, for example, as Damping Fluid, Type 200, viscosity rating 350 centi-stokes, this being a silicone base fluid as manufactured by the Dow Chemical Co., Midland, Mich. This fluid is poured in through the aforesaid filling opening which is then closed by the screw plug 371, the top of this plug thereafter being sealed to the main body 320, as by soldering.

The inertia switch mechanism SW-3, which fires the torpedo upon impact with the target, is shown in Fig. 9. This mechanism is fully described, illustrated, and claimed in the copending application of James M. Kendall et al., entitled Inertia Switch for Torpedo Exploder, Serial No. 780,5 62, filed October 17, 1947. This device is enclosed by a cup-shaped cylinder 385 of suitable insulating material, for instance a phenolic condensation product such as Bakelite, and having a bottom disc 386 in which is formed mounting holes 387. The cylinder 385 has a circumferential rim 388 to which a 12 cover 390, likewise of suitable insulating material and having a central opening 391, is secured by a flanged ring 389, this ring being beaded about the under face of the circumferential rim. The cylinder 385 has an axial bore 395 therein which is encased on the bottom and on the side wall by a liner of copper, bronze, brass, or the like, this liner being connected by a pig tail conductor 398 to a terminal post 392 extending through the opening in cover 390 of the switch. The liner is made in two (2) sections, a hemispherical section 396 positioned in the bottom of the cylinder and in part in the bore 395 and a cylindrical section 397 positioned entirely in the bore itself and terminating in a rounded closed end. The open end of the cylindrical section partially encompasses the hemispherical section 396 at the open top of the latter, the two (2) sections being electrically connected together, as by soldering or brazing. A hollow insert 401, of neoprene rubber or other suitable material, is mounted within the cylindrical section 397 of the liner by a close fit, this insert having a bottom 402, a central hole 403 therethrough, a counterbore 404 in the bottom, and a main cylindrical bore 405. A second hollow insert 406 is interposed between the rounded end portion of liner section 397 and insert 401 to form an internal shoulder 407 between the inserts.

An inertia element 408 has a head of considerable mass and a cylindrical stem 410, the head having an axial bore therein which receives the stem. The head is held to the stem by a transversely positioned set screw 409. The stem has an abutment disc 411 on the outer end thereof, this abutment disc having a shoulder 412 on its inner face concentrically formed with respect to the axis of the stem. A coiled compression spring 413 surrounds the stem and has one end positioned in the counterbore 404 in the bottom of the insert 401 and the other end surrounding the shoulder 412 on the abutment disc 411. The abutment disc is connected by a pig tail conductor 414 to a second terminal post 393. Conductor 414 also extends through the opening in the cover 390 of the switch and has a rigid conductor portion 382 which extends through a central opening in liner section 397 and is insulated and supported therefrom by the glass insulation 383 and the flange 400 respectively, the conductor 394 and flange 400' preferably being made of Kovar. With the various parts in their normal positions, the compression spring 413 yieldably urges the abutment disc against shoulder 407 between the inserts whereby the massive head is spaced some distance from the bottom of the hemispherical section 396 of the metal mer.

The wiring diagram of the firing circuit for the exploder is best shown in the schematic view of Fig. 1. Battery BA is connected by the conductor 415 to the contact blade member 287 of the arming switch SW-l, the other contact blade member 289 thereof being connected to a resistor R-l by the conductor 416. The resistor R-1 is connected by a conductor 417 to one terminal of the inertia switch SW-3, the other terminal of which is connected by a conductor 418 to one terminal of the electroresponsive squib 260. The other terminal of battery BA is connected by a conductor 419 to the other terminal of the electroresponsive squib. A resistor R-2 and capacitor C are connected in parallel across the series connection including battery BA, arming switch SW-1 and resistor R-l. The fluid pressure actuated differential switch SW2 in series with a resistor R3 is con nected in parallel relationship with the capacitor C.

In operation, the torpedo is launched in the water, usually from a submarine located below the surface, and the homing mechanism is so arranged as to cause the torpedo to strike the target vessel below the water line and preferably on its keel. The torpedo will be propelled through the Water by whatever motive means is incorporated therein, such as an electric motor or a steam or a compressed air turbine. In the course of its easiest...

, 13 travel through the water, sage 131 between the guard plate 129 and the bottom plate 126 on the, exploder mechanism 80 and passes, through the eXit aperture 132. The jet action of the water. through the Venturi passage 131 causes the impeller wheel 135 to be rotated and the rotation of the latter is transmitted through the transmission comprised by the worm gearing 142157, the countershaft 144, the spur gearing 162164, the elongated driving shaft 165, and theworm gearing 295266 to the rotary disc 271 R- tation of the disc 270 is stopped short of a full revolution when the spring pressed detent 306 enters hole 278 (Fig. 6) in the cover plate 226. The ratios of the gear trains 142-..157, 162164, and 295-266 are so chosen that the rotary disc 270 will be locked after the torpedo has travelled from one hundred (100) to three hundred (300) yards through the water. Thereafter, further rotation of the impeller wheel 135 will not cause additional rotation of the rotary disc 270 for the reason that the clutch sleeve 293, now moves downwardly (Fig. 4-) against the compression of the spring 299 until the square section 296 in the bore 294 is no longer in engagement with the complementary square section 166 on the driving shaft 165 whereby relative motion takes place between the driving shaft and the clutch sleeve. With the rotary disc 270 in the described locked position, a detonator 275 is in alignment with the electroresponsive squib 260 and with the tetryl lead 265, and the wiping contact blade 235, also carried by the rotary disc 27%, is in engagement with the contact blade members 287 and 239, thereby completing the arming circuit. The detonator train is now complete and the arming circuit is closed.

In the case of an ordinary torpedo fired from an underwater position, accurate aiming of the torpedo is not always possible and, of course, even a torpedo fired from a surface vessel may depart from the line of aim with the target. However, in the case of a homing torpedo, themicrophones 36-496 in the nose of the torpedo willpick up the noise of vibration of the propellers on thetarget vessel and will transform these vibrations into electrical impulses which are transmitted to the automatic steering apparatus mounted in the rear compartment of the torpedo, which apparatus will guide the torpedo toward the target, substantially in a manner described, for example, in US. Patent No. 1,121,563 to KarlO. Leon. Should the torpedo miss the target vesse l the microphones 36.36 will continue to pick up noise of vibrations of the propellers of the target vessel and the automatic steering apparatus will cause the torpedo to turn in its course and make a return run and a second strike at the target vessel.

When the torpedo strikes the target vessel, the force ofthe impact will actuate the inertia switch SW-3. The massive head 408 on the cylindrical stem 410 will overcome. the resistance of the spring 413 and strike the hemispherical section 396 of the liner, thereby connecting the capacitor C to the electroresponsive squib 260 whereby the squib is detonated. The detonation of the electroresponsive squib causes sequential firing of the detonator 275, the tetryl lead 265, the sub-booster charge 255, the booster charge 35, and the main explosive charge 15.-

In the case of a torpedo fired from an underwater position and approaching the target vessel in an upsweep intended to cause the torpedo to strike the keel of the vessel, should the torpedo miss the target vessel and move out of the water, the force of the impact upon reentering the water would also actuate the inertia switch SW-3 and likewise fire the torpedo. The explosion of the torpedo would apprise the target vessel of the fact that-it is under attack, and the destruction of the torpedo would render it unable to make a return run and asecond strike at the vessel. In the case of a surface running torpedo, it would be similarly fired by impact Water en er he Venturi Past if it should passfrorn the crest of one large wave, over the trough, and into the crest of the next wave. With the firing circuit of the present invention, however, thev differential fluid pressure actuated switch SW4; shortcircuits the capacitor whenever the torpedo is out of the water, thereby preventing firing of the squib by the charge on the condenser.

As long as the torpedo is running below the surface ofthe water, water under pressure will be transmitted from the nose through the conduit 65, the annular groove 107 in the bottom flange 86. of the cylindrical base 31 of the exploder mechanism, the transverse bore 117 and the,

longitudinal bore 122 in thecylindrical base, and the conduit 201 to the chamber comprised by the bore 332, Fig. 7, in the hub 328 of the fluid pressure actuated differential switch SW-2, where it is applied to the diaphragm 342. Similarly, negative dynamic pressure is transmitted through the conduit 75, this conduit having its inlet end positioned at 70, the point of maximum negative dynamic pressure, as shown in Fig. 8, the negative dynamic pressure causing reduced pressure in the annular groove 111 in the bottom flange 86 of the cylindrical base 81 of the eXploder mechanism, the transverse bore 114. and the longitudinal bore 119 in the cylindrical base, and the conduit 196 to the bore 325, Fig. 7, in the hub 329 of the fluid pressure actuated differential switch SW-Z, where it is applied to'the diaphragm 343. The dynamic pressure acting on-the diaphragm 342 forces the piston 356 and its stem 358 inwardly and the contact disc 366 away from the contact rings 382 and 384 carried by the contact rods 378 and 380, respectively, this motion of the piston and its stern being opposed by the spring 369. The negative dynamic pressure operating on the diaphragm 343 aids the inward movement of the piston 356 and its stem 358 by reducing the back pressure in the chamber comprised by the main bore 343 in the body 320 of the switch. Thus, as long as the torpedo is running below the surface of the water, the combined action of the water pressure on the nose of the torpedo and the negative pressure at the point 70 on the side thereof will hold the contact disc 366 away from the contact rings 332 and 384 whereby the circuit connected to these rings is held open. Should the torpedo move out of the water, however, the dynamic pressure will cease to exist in conduit 201 and the negative dynamic pressure transmitted through the conduit 196 will be relieved, thereby causing the piston 356 and stem 358 to move instantly in the opposite direction under power of spring 369' to cause the contact disc 3&6 to engage the contact rings 382 and 384 whereby the capacitor C is substantially instantly discharged and the exploder thereby sterilized until after the nose of the torpedo has reentered the water. The resistor R-3 is of sufiicient value to limit the value of the discharge current from capacitor C, thereby to prevent sticking or welding of the contact disc 366 to the contact rings 382 and 384 as the discharge current flows therethrough.

When arming switch SW-l is closed, and after eachbroach of the torpedo, the capacitor C is charged from battery BA by way of the arming switch SW1 and resistor R-l. Resistor R-l limits the rate of charging of the capacitor C so that it is not fully charged until a pre determined interval, corresponding approximately to the RC time of resistor R-1 and capacitor C, has elapsed following opening of the diflerential switch SW-2 as the torpedo recovers from the broach, thereby insuring that the exploder will not be actuated by shock of impact of the torpedo with the surface of the water as a result of the broach. Resistor R-2 is a relatively high value resistor and serves to discharge the capacitor C when the torpedo is unarmed, thereby to prevent firing of the electroresponsive squib by a charge on capacitor C in the event. that the inertia switch SW3 is closed, as by a shockin the handling or launching of the torpedo, when arming switch SW-lis. open. a

' While there is shown and described herein a certain preferred embodiment of the invention which gives satisfactory results, it will be understood that many other and varied forms and uses will present themselves to those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

The invention herein described and claimed may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a torpedo, the combination of a firing circuit including a normally charged condenser and an electroresponsive detonator, inertia means for rendering said condenser effective to fire the detonator upon impact of the torpedo with its target, and means including a pressure differential switch in hydraulic communication with the surrounding water and a time delay means therefor respectively and operatively connected to the firing circuit for rendering the condenser ineffective to fire the detonator during a predetermined time interval as said inertia means operates in response to the impact of the torpedo with the surface of the water following a breach thereof.

2. In a torpedo, the combination of a firing circuit ineluding an electroresponsive detonator, normally open inertia switch means for rendering said circuit effective to fire the detonator upon impact of the torpedo with its target, a capacitor serially connected in said circuit between said detonator and said inertia switch means for supplying the energy to fire the detonator, a source of electrical energy operatively connected to said capacitor for placing an electric charge thereon, a resistor operatively connected between said capacitor and said source to establish a predetermined time constant for the charging of the capacitor, and means including a normally open pressure switch having the high and low pressure sides thereof in fluid communication with the exterior of the torpedo at the nose and side wall thereof respectively and responsive to the difference in dynamic pressure of the surrounding water between the nose and the side wall of the torpedo for rendering the firing circuit ineffective to fire the detonator as the inertia means operates in response to the impact of the torpedo with the surface of the water following a broach thereof, said pressure switch being connected across the capacitor in short circuiting relationship therewith.

3. In a torpedo, the combination of a firing circuit including an electroresponsive detonator, time delay means for arming the firing circuit in predetermined time delayed relation to the initiation of the operation of the time delay means, pressure differential responsive means adapted to render the firing circuit ineffective to fire the detonator when the torpedo is in broach and adapted to initiate operation of the timing means when the difference in the dynamic pressure of the surrounding water between the nose and side wall of the torpedo reaches a predetermined value, and inertia means effective when the firing circuit is armed to render the firing circuit effective to fire the detonator as the inertia means operates in response to the impact of the torpedo with its target.

4. In a torpedo, the combination of an electroresponsive detonator, an energy storage device, a circuit including an inertia responsive switch for causing the detonator to be fired by the energy in said storage device as the inertia switch operates in response to the impact of the torpedo with its target, a fluid pressure differential responsive switch including normally disengaged switch elements electrically connected to opposite sides of said storage device respectively said pressure differential responsive switch further including movable diaphragm means in hydraulic communication with the exterior of the nose and side wall portions respectively of the'torpedo and mechanically connected to said switch elements respecr termined value.

5. In a torpedo, the combination of an electroresponsive detonator, an energy storage device, a fluid pressure, differential responsive switch including normally d1Se1'l-' gaged switch elements electrically connected to opposite sides of said storage device respectively said pressure dif-v ferential responsive switch further including movable diaphragm means in hydraulic communication with the exterior of the nose and side wall portions respectively of the torpedo and mechanically connected to said switch.

elements respectively for effecting engagement thereof tothereby discharge the energy in said storage device whenv the diflerence in the dynamic pressure of the surrounding water between the nose and side wall of the torpedo is less than a predetermined value, means adapted to be.

rendered effective when the difference in the dynamic pressure exceeds said predetermined value to store sufficient energy in the storage device to fire the detonator,

means for storing said energy in the storage device at a predetermined rate whereby a predetermined lnterval of time is caused to elapse before said suflicient amount of energy is stored in the storage device, and a circuit in-,.

cluding an inertia responsive switch for causing the detonator to be fired by the energy in said storage device as the inertia switch operates in response to the impact of the torpedo with its target.

6. In a torpedo, the combination of a firing circuit including an electroresponsive detonator, time delay means for arming the firing circuit in predetermined time delayed relation to the initiation of the operation of the time delay means, fluid pressure differential responsive means for initiating operation of the time delay means when the difference in the dynamic pressure of the surrounding water between the nose and side wall of the' torpedo reaches a predetermined value, and inertia switch' means effective when the firing circuit is armed to close the firing circuit thereby to fire the detonator as the inertia switch means operates in response to the impact of the torpedo with its target.

7. In a torpedo, the combination of a firing circuit including an electroresponsive detonator, time delay meansfor arming the firing circuit in predetermined time delayed relation to the initiation of the operation of the time delay means, fluid pressure differential responsive means for initiating operation of the time delay means when the dif-' ference in the dynamic pressure of the surrounding water between the nose and side wall of the torpedo reaches a predetermined value and adapted to render the firing circuit ineffective to fire the detonator when said difference in the dynamic pressure of the surrounding water is less than said predetermined value, and inertia switch means effective when the firing circuit is armed to close the firing circuit thereby to fire the detonator as the iner tia switch means operates in response to the impact of the torpedo with its target.

8. In a torpedo, the combination of an explosive train including an electroresponsive detonator and a movable explosive element initially positioned out of operative firing relation with respect to the detonator, a. source of energy, an energy storage device, an initially open switch interconnecting said source of energy and said storage device, means including an impeller wheel adapted to be rotated in response to the movement of the torpedo through the water for closing said switch and moving said explosive element into operative firing relation with respect to said detonator when the impeller wheel has made a predetermined number of revolutions, means for causing energy from said source to be stored in said stor:

17 age device at a predetermined rate when said switch is closed, a fluid pressure differential responsive switch including normally disengaged switch elements electrically connected'to opposite sides of said storage device respectively, said pressure differential responsive switch further including movable diaphragm means in hydraulic communication with the exterior of the nose and sidewall portions respectively of the torpedo and mechanically connected to said switch elements respectively for effecting engagement thereof to thereby discharge the energy stored in the storage device when the difference in the dynamic pressure of the surrounding water between the nose and the side wall of the torpedo is less than a predetermined value, and a normally open inertia switch connected between the detonator and the energy storage device for causing the detonator to be fired by the energy stored in the storage device as the inertia switch closes in response to the shock of impact of the torpedo with its target.

9. In a torpedo, the combination of an electroresponsive detonator, a source of electrical energy, means for discharging said source of energy through the detonator upon impact of the torpedo with its target, and means including a pressure differential switch having normally disengaged switch elements after the torpedo has been launched, said switch elements being respectively connected to opposite sides of said source of energy and in operative fluid communication with the exterior of the torpedo and at portions thereof upon which the surrounding water exerts different dynamic pressures whereby said switch elements are normally disengaged while the torpedo is submerged for short circuiting the source of energy when the torpedo is on a broach and the switch elements are in conducting engagement with one another.

10. In a torpedo, the combination of an electroresponsive detonator, a source of electrical energy, means for discharging said source of energy through the detonator upon impact of the torpedo with its target, and means for short circuiting the source of energy when the torpedo is in broach, said last named means comprising a fluid pressure actuated switch normally closed prior to the launching of the torpedo and including disengaged switch elements electrically connected to opposite sides of said source of energy respectively and further including movable diaphragm means in hydraulic communication with the exterior of the nose and side wall portions respectively of the torpedo and mechanically connected to said switch elements respectively in accordance with the pressure differential acting upon said diaphragm means, said switch elements being disengaged in response to a predetermined difference in dynamic pressure between the nose and the side wall of the torpedo after the launching thereof and engaged during broach of the torpedo.

11. In a torpedo, the combination of an electroresponsive detonator, an electrical energy storage device, means for storing electrical energy in said storage device, circuit means including an inertia responsive switch for causing the detonator to be fired by energy from said storage device upon impact of the torpedo with its target, and means for short circuiting the energy storage device when the torpedo is in broach, said last named means comprising a fluid pressure actuated switch normally closed prior to the launching of the torpedo and including switch elements electrically connected to opposite sides of said storage device respectively and further including movable diaphragm means in hydraulic communication with the exterior of the nose and side wall portions respectively of the torpedo and mechanically connected to said switch elements respectively for effecting engagement and disengagement thereof in accordance with the pressure differential acting upon said diaphragm means, said switch elements being disengaged and the pressure actuated switch opened in response to a predetermined difference in the dynamic pressure between the nose and side wall of the torpedo after the launching thereof and the switch elements being engaged and the l8 pressure actuated switch closed during broach of the torpedo.

12. In a torpedo, the combination of an electroresponsive detonator, a capacitor, means for short circuiting the capacitor when the torpedo is in broach, a battery, a resistor, means for charging the capacitor from said battery and through said resistor whereby the capacitor is charged to a predetermined amount in predetermined time delayed relation to the recovery of the torpedo from a broach thereof, and means for causing the detonator to be fired by the charge on the capacitor upon impact of the torpedo with its target.

13. In a torpedo, the combination of an electroresponsive detonator, a capacitor, means for short circuiting the capacitor when the torpedo is in broach, a resistor, means including a battery for charging the capacitor through said resistor whereby the capacitor is charged to a predetermined amount in predetermined time delayed relation to the recovery of the torpedo from a broach thereof, an arming switch adapted to be closed to conneot said resistor to the battery when the torpedo has travelled a predetermined distance through the water f0llowing launching thereof, and means for causing the detonator to be fired by the charge on the capacitor upon im' pact of the torpedo with its target.

14. In a torpedo, an electroresponsive detonator, a capacitor, a firing circuit including said detonator and capacitor, an inertia switch adapted to connect the capacitor to the detonator in response to the impact of the torpedo with its target, means for charging the capacitor comprising a battery, a resistor in series with the capacitor and the battery, and an arming switch adapted to connect the battery to the resistor when the torpedo has travelled a predetermined distance through the water following launching thereof, a second resistor in parallel with the capacitor for discharging the capacitor when the arming switch is open, and a differential pressure responsive switch normally closed prior to the launching of the torpedo and having switch elements electrically connected to opposite sides of the capacitor respectively and further including movable diaphragm means in hydraulic communication with the exterior of the nose and side wall portions respectively of the torpedo and mechanically connected to said switch elements respectively for effecting engagement and disengagement thereof in accordance with the pressure differential acting upon said diaphragm means, said switch elements being disengaged and the pressure actuated switch opened in response to a predetermined difference in the dynamic pressure between the nose and the side wall of the torpedo and for short circuiting the capacitor as the differential pressure responsive switch closes in response to a broach of the torpedo.

15. In a torpedo, an electroresponsive detonator, 8. capacitor, a firing circuit including said detonator and said capacitor, an inertia switch adapted to connect the detonator to the capacitor in response to the impact of the torpedo with its target thereby to fire the detonator by the charge on the capacitor, means for charging the capacitor comprising a battery and a first resistor connected to the capacitor and adapted to be connected to the battery, an arming switch adapted to connect the battery to the resistor when the torpedo has travelled a predetermined distance through the water following launching thereof, a second resistor in parallel with the capacitor, switch means for short circuiting the capacitor during broach of the torpedo, and means for preventing arcing of the switch means by discharge of the capacitor therethrough.

16. In a torpedo, the combination of an electrorespom sive detonator, a capacitor, a differential pressure responsive switch for short circuiting the capacitor when the torpedo is in broach and having movable switch elements respectively connected to opposite sides of said capacitor, movable diaphragm members respectively and mechanically connected to said switch elements and hydraulically 19 connected to the exterior of the torpedo at the nose and side wall portions thereof respectively to thereby move the switch elements into engagement and disengagement selectively in accordance with difierential pressures of References Cited in the file of this patent predetermined magnitudes respectively, a battery, 21 resis- 5 tor, means for charging the capacitor from said battery and through said resistor whereby the capacitor is charged to a predetermined amount in predetermined time delayed relation to the recovery of the torpedo from a broach thereof, and means for causing the detonator to be fired 1 UNITED STATES PATENTS Breeze et a1. Apr. 29, 1947 

